PMs, RTFM or GTFO!
Do PMs actually know the basics of product management?
While I am not a fan of Marty Cagan’s utopic Inspired, any product manager with a few years of experience ought to have read it, and formed an opinion on its relevance. Imagine my surprise when recently I spoke with a Group Product Manager who said they had yet to “finish it.” How do you become a manager of product managers, not having read that book? At 300+ pages, it’s doable in a weekend. I also happened to converse with a Senior Product Manager who is poised to become a Staff Platform PM, yet had not heard of any book on product psychology or platforms. Another person had completed an imagined user journey map based on a handful of interviews. When asked why they had not simply mapped the steps involved by going through the product themselves, they appeared flabbergasted.
These conversations made me wonder: Do product managers even read the books that define their area of alleged expertise?
Product managers in the world
There are estimated to be between 700,000 and 850,000 product managers in the world. With 28.7 million software developers, 1.5 million of whom are freelancers, we have a PM-to-dev ratio of 1:32, which is much higher than the typical values of 5–10 developers per product manager. Of course small companies or even traditional enterprises outside of tech may forgo the formal role of product manager, or they have product owners, business solution managers, project managers, and so on to fulfil that role. These people are not included. And then there are homeopathic product managers who skew the results anyway.
For the sake of argument, let’s round it up to 1 million product managers worldwide. If they know the core literature of their field, I would expect these books to have sold on that order of magnitude. Maybe not exactly because of piracy, but close enough. Let’s see if that assumption holds.
How to estimate book sales from amazon.com reviews
For non-fiction, about 1% of people who purchase a book also leave a review on Amazon. In rare cases do 3–5% of people review a book they bought, but 1% is good enough for establishing an upper bound on the number of books sold based on reviews alone. After all, the fewer people review, the more each review counts towards books sold.
Sales of any goods on amazon.com account for almost 70% of global sales of the company. Let’s assume that ratio is the same for books.
Amazon has a market share in books and audiobooks of 50–60% in most countries. Let’s pick the middle: 55%.
In other words,
- For every review on amazon.com, 100 books were sold there.
- For every book sold on amazon.com, there were 1/0.70 ≈ 1.43 books sold on Amazon globally.
- For every copy sold on Amazon, there were 1/0.55 ≈ 1.81 books sold in total.
With that we can estimate the number of books sold from the number of reviews on amazon.com: just multiply the number of reviews by 260 ≈ 1/0.01 · 1/0.70 · 1/0.55. Is that accurate? Not necessarily, but without access to a paid solutions like Nielsen BookScan, it is acceptable.
Books
How many product managers have read standard books in the field? In the following table I have included key books from product management and related fields too. The PM coverage column contains an estimate of the percentage of product managers (rounded to multiples of five) that may have read each book based on the sales figures. Where these are known, they are shown rather than the estimate from amazon.com reviews as outlined above. The data is as of 1 August 2025.
For literature on product management, the core assumption is that the readership is exclusively product managers. This is not necessarily true, but it provides an upper bound; any product management books read by non-PMs require more copies to be sold to have a higher coverage among PMs. In reality, the share of PMs that have actually read said books will be much lower, as business leaders, entrepreneurs, product-savvy engineers, and so on also tend to pick up such volumes. For books outside of the product management category, I have assumed that only a quarter of their readers are PMs.
What does that mean? If a book within product management has sold 500,000 copies, the PM coverage shows 50%, as there are one million product managers on the planet. And if the book is related to any other category, then we divide 500,000 by four, and compare that to the one million PMs worldwide. That yields 12.5%, which is rounded to multiples of five, so 15%.
| Title | Author(s) | Category | First published | Reviews on amazon.com | Copies sold | PM coverage |
|---|---|---|---|---|---|---|
| Blue Ocean Strategy | Chan Kim & Renée Mauborgne | Strategy | 2005 | 6,094 | >4 million | 100% |
| The Hard Thing About Hard Things | Ben Horowitz | Leadership | 2014 | 15,072 | est. 4 million | 100% |
| Good to Great | Jim Collins | Leadership | 2001 | 9,382 | >4 million | 100% |
| Measure What Matters | John Doerr | Product management | 2018 | 9,633 | est. 3 million | 100% |
| Hooked | Nir Eyal & Ryan Hoover | Psychology | 2014 | 9,221 | est. 2 million | 50% |
| Nudge | Richard Thaler & Cass Sunstein | Psychology | 2008 | 4,045 | >2 million | 50% |
| Inspired | Marty Cagan | Product management | 2017 | 6,029 | est. 2 million | 100% |
| The Design of Everyday Things | Don Norman | UX | 2013 | 8,261 | est. 2 million | 50% |
| Drive | Daniel Pink | Psychology | 2011 | 9,062 | >2 million | 50% |
| Build | Tony Fadell | Entrepreneurship | 2022 | 2,890 | est. 1 million | 25% |
| Cracking the PM Interview | Rayle Laakmann McDowell & Jackie Bavaro | Product management | 2013 | 3,170 | est. 1 million | 100% |
| Crossing the Chasm | Geoffrey Moore | Strategy | 2014 | 2,502 | >1 million | 25% |
| The Mom Test | Rob Fitzpatrick | Product management | 2013 | 3,803 | est. 1 million | 100% |
| Good Strategy / Bad Strategy | Richard Rumelt | Strategy | 2011 | 5,123 | est. 1 million | 25% |
| Made to Stick | Chip Heath & Dan Heath | Psychology | 2007 | 5,170 | est. 1 million | 25% |
| The Lean Startup | Eric Ries | Entrepreneurship | 2011 | 17,282 | >1 million | 25% |
| Zero to One | Peter Thiel & Blake Masters | Entrepreneurship | 2014 | 38,588 | >1 million | 25% |
| Start with Why | Simon Sinek | Leadership | 2011 | 24,234 | >1 million | 25% |
| Swipe to Unlock | Neel Mehta et al. | Growth | 2017 | 2,809 | est. 730000 | 20% |
| Don’t Make Me Think | Steve Krug | UX | 2013 | 4,561 | >700,000 | 20% |
| Continuous Discovery Habits | Teresa Torres | Product management | 2021 | 2,526 | est. 660000 | 65% |
| Traction | Gabriel Weinberg & Justin Mares | Growth | 2015 | 2,006 | est. 520000 | 15% |
| The Innovator’s Dilemma | Clayton Christensen | Strategy | 1997 | 69 | >500,000 | 15% |
| Sprint | Jake Knapp et al. | UX | 2016 | 4,653 | >500,000 | 15% |
| Platform Revolution | Geoffrey Parker et al. | Platforms | 2017 | 1,829 | est. 480000 | 10% |
| User Story Mapping | Jeff Patton & Peter Economy | Product management | 2014 | 1,643 | est. 430000 | 45% |
| Product-Led Growth | Wes Bush | Growth | 2019 | 1,602 | est. 420000 | 10% |
| Hacking Growth | Sean Ellis & Morgan Brown | Growth | 2017 | 1,509 | est. 390000 | 10% |
| The Lean Product Playbook | Dan Olsen | Product management | 2015 | 1,388 | est. 360000 | 35% |
| Outcomes over Output | Joshua Seiden | Product management | 2019 | 1,093 | est. 280000 | 30% |
| The Product Book | Carlos González de Villaumbrosia et al. | Product management | 2017 | 882 | est. 230000 | 25% |
| The Professional Product Owner | Don McGreal & Ralph Jocham | Product management | 2018 | 830 | est. 220000 | 20% |
| Product Management’s Sacred Seven | Neel Mehta et al. | Product management | 2020 | 846 | est. 220000 | 20% |
| Actionable Gamification | Yu-kai Chou | Psychology | 2015 | 851 | est. 220000 | 5% |
| Lean Analytics | Alistair Croll & Benjamin Yoskovitz | Product management | 2024 | 811 | est. 210000 | 20% |
| Product Roadmaps Relaunched | Todd Lombardo et al. | Product management | 2017 | 767 | est. 200000 | 20% |
| Agile Product Management with Scrum | Roman Pichler | Product management | 2010 | 681 | est. 180000 | 20% |
| Lean UX | Jeff Gothelf & Josh Seiden | UX | 2016 | 627 | est. 160000 | 5% |
| Jobs To Be Done | Anthony Ulwick | Strategy | 2016 | 502 | est. 130000 | 5% |
| Product Management for Dummies | Brian Lawley & Pamela Schure | Product management | 2012 | 516 | est. 130000 | 15% |
| Monetizing Innovation | Madhavan Ramanujam & Georg Tacke | Strategy | 2016 | 497 | est. 130000 | 5% |
| Product Leadership | Richard Banfield | Leadership | 2017 | 471 | est. 120000 | 5% |
| Nail It, Then Scale It | Nathan Furr & Paul Ahlstrom | Entrepreneurship | 2011 | 336 | est. 90000 | 0% |
| Business of Platforms | Michael Cusumano et al. | Platforms | 2019 | 298 | est. 80000 | 0% |
| Escaping the Build Trap | Melissa Perri | Product management | 2018 | 1,696 | >75,000 | 10% |
| Product Management in Practice | Matt LeMay | Product management | 2017 | 282 | est. 70000 | 5% |
| Product Operations | Melissa Perri & Denise Tilles | Product management | 2023 | 220 | est. 60000 | 5% |
| The Product Manager’s Survival Guide | Steven Haines | Product management | 2013 | 193 | est. 50000 | 5% |
| Principles of Product Management | Peter Yang | Product management | 2020 | 168 | est. 40000 | 5% |
| Designing for Behaviour Change | Stephen Wendel | Psychology | 2020 | 163 | est. 40000 | 0% |
| Product Direction | Nacho Bassino | Product management | 2021 | 97 | est. 30000 | 5% |
| Start at the End | David Lavinsky | Entrepreneurship | 2012 | 113 | est. 30000 | 0% |
| Product-Led Organization | Todd Olson | Growth | 2020 | 83 | est. 20000 | 0% |
| Engaged | Amy Buchner | Psychology | 2020 | 80 | est. 20000 | 0% |
| Disciplined Entrepreneurship | Bill Aulet | Entrepreneurship | 2024 | 62 | est. 20000 | 0% |
| Next-Gen Product Management | Teresa Cain et al. | Product management | 2025 | 29 | est. 10000 | 0 % |
| The Product-Led Playbook | Wes Bush | Growth | 2024 | 53 | <10,000 | 0% |
| Platform Engineering | Camille Fournier & Ian Nowland | Platforms | 2024 | 41 | est. 10000 | 0% |
In the product management category, we find a median of 19%, based on unrounded values for PM coverage. If 3% of people leave a review on amazon.com rather than 1%, that figure drops to 7%. Across categories, we see the following when 1% of shoppers leave a review:
| Category | Median PM coverage |
|---|---|
| Psychology | 25% |
| Product management | 19% |
| UX | 16% |
| Leadership | 14% |
| Entrepreneurship | 14% |
| Strategy | 13% |
| Growth | 11% |
| Platforms | 2% |
Overall, it seems that purely based on sales figures and a few mild assumptions, a minority of product managers actually read books related to their field.
While books are not the only path to mastery, their systematic coverage of fundamentals remains unmatched. But what if PMs prefer to listen rather than read? Let’s investigate!
Podcasts
One of the most popular podcasts in product management is Lenny’s Podcast with Lenny Rachitsky, which counts 266 episodes. He claims to have 20 million downloads, so a little over 75,000 people who have listened to each episode. The podcast has 405,000 subscribers on YouTube alone. Product School counts 142,000 YouTube subscribers, Masters of Scale has 134,000, Leah Tharin’s ProducTea with Leah sports 33,200 subscribers on YouTube, and Melissa Perri’s Product Thinking has only 2,170. And so on.
Again, podcasts cannot fill in the gaps for so many product managers who refuse to read their area’s literature.
What about massive open online courses (MOOCs)? Maybe PMs are more into that than plain ol’ books or podcasts!
MOOCs
Coursera offers a few courses and specializations, yet not a single one has more than 100,000 people enrolled. Since completion rates for MOOCs are below 13%, that means fewer than 13,000 people complete each course. Similarly, there are 175 courses and videos on edX related to product management, which includes many materials only tangentially related to the field. The fundamentals course has 77k students, so only 10,000 have actually finished it. Udemy has 360 courses for product management with 1.4 million learners. That said, most courses are only a few hours, so hardly the stuff of legends. And with completion rates as they are, that only accounts for 182k product managers who managed to sit through all the content. All in all, MOOCs cannot teach so many product managers the basics of product management either.
Platforms like Maven and Reforge do not publish subscribers. Completion rates are probably higher than most MOOCs, because they are more expensive and cohort-based. A cursory look at a few courses on Maven shows 25–40 sign-ups per week with four cohorts a year. That amounts to under 2,100 people per year who subscribe to a single course. Even with 100 available courses, that amounts to less than 15% of the global product management population. Note that embedded in that figure is the improbable assumption that the same PMs do not do more than one course per year.
Perhaps most product managers rely on mentors or company-internal courses. Mentors are an unlikely source of foundational education, as there are too few knowledgeable PMs anyway. And they are not supposed to be teachers, especially for basics that can be picked up from many a source and format. Company-internal courses are rare in startups and SMEs, which leaves enterprises. From personal experience, internal seminars at enterprises are rarely worth the effort as they cater to the lowest common denominator. Maybe that is exactly the level required, but I still doubt anyone who claims that is where most product managers pick up the basics. F(l)ailing on the job is more probable.
Conclusion
There are very few formal degree programmes at universities to become a product manager. An MBA is often seen as a ticket into product management, with 10% choosing to become product managers after receiving an education that is geared towards business and people management rather than product management. As an aside, I suspect that is mostly because they are the business equivalent of art teachers: if they could make great art (i.e. run a successful business), they would do it rather than teach (i.e. become product managers).
People who enter the field therefore have to learn the ropes on the job. Books, podcasts, MOOCs, and so on are available, yet from the analysis in this post it is obvious that too few use the opportunities at their disposal. Less than a fifth of all product managers are familiar with the canonical literature. Statistically, that includes plenty of senior folks. That is a massive concern, though it does not surprise me as the field is full of faux experts who pass the interviews by sounding reasonable yet without substance, because the people charged with hiring are equally oblivious.
You wouldn’t trust a surgeon who skipped anatomy classes. You wouldn’t fly with a pilot who ignores flight manuals. You wouldn’t cross a bridge built by a mechanical engineer who thinks physics is overrated. So, why do we celebrate product managers who wing it with zero foundational knowledge?
My advice? RTFM or GTFO!